Automatic machines for the preparation of drinks are known, in which single-dose or single-use cartridges are used, containing the ingredients of the drink. To prepare a drink, a cartridge corresponding to the desired drink is inserted by the user into a cartridge path that comprises a brewing chamber, where the apparatus automatically provides for preparing the drink by making water pass through the cartridge itself. Apparatuses of this type are known and widespread above all for the preparation of hot drinks, such as coffee, tea, chocolate and the like, but sometimes the preparation of cold drinks is also provided, such as typically flat soft drinks.
The drink is obtained either by infusion of the ingredients of the cartridge into the brewing water (typical method for coffee and tea) or by dissolving of the ingredients themselves into the water (typical method for cold drinks and for some hot drinks). According to the case, the brewing water is therefore previously heated or cooled to the temperature suitable for the preparation of the specific drink.
The drink thus produced is conveyed towards a dispenser, below which a suitable container, such as a plastic cup or a jug, has previously been arranged.
The cartridges can comprise a casing made from filtrating material containing the ingredients for the drink, or else can be made from a material impermeable to air and water with a plastic body in which the ingredients for the drink are sealed by a deformable laminate sheet: in this case the brewing water is made to pass inside the cartridge after perforation of the cartridge itself at a predetermined entry point for the water and at a predetermined exit point for the drink.
According to the level of automation of the apparatus, some functions can be carried out automatically, such as the determination of amount, temperature, and possible pressure of the water, the movement of the cartridge in its path, the choice of the type of cup and its arrangement in position, the possible dispensing of sweetener and the selection thereof, the possible dispensing of a spoon and the possible dispensing of further additional products such as milk, cream, chocolate powder, etc.
To be possible to automate the preparation cycle of the drink, it is necessary for the apparatus to know what drink must be prepared from the many for which it is normally set. For such a purpose apparatuses are known that use optical readers that read codes arranged on the cartridges and that communicate the reading to a control unit of the apparatus; the control unit can thus recognise what drink must be prepared with the cartridge that has been inserted and consequently can activate the specific preparation cycle for such a drink.
Even if the preparation cycle of the drink is the same for all types of drink, the reading of the code can provide useful information to the control unit, such as the expiry date of the ingredients contained in the cartridge, the compatibility of the type of cartridge with the apparatus, etc.
By optical code we mean to indicate a group of graphical symbols through which a piece of information is coded as a sequence of white zones and black zones or else variously coloured zones, arranged according to one or more directions. Examples of such codes are barcodes, stacked codes, two-dimensional codes, colour codes and others. By optical code we also mean a string of alphanumeric characters, stamps, logos, signatures or other symbols having the function of coding information.
In general, an optical reader comprises on one side a light source and an optical illumination or scanning path that extends from the light source towards the code, and on the other side an optical sensor and an optical image formation system, arranged in an optical image reception path that extends from the code to the optical sensor; all of this is arranged in a suitable housing, provided with at least one window, through which preferably pass both the optical illumination path and the optical image reception path, i.e. both the light that goes from the light source to illuminate the code and the light that goes towards the sensor from the illuminated code. The optical image formation system is a group of optical components (such as, typically, mirrors, lenses and possibly also diaphragms) for collecting and focusing the image of the code on the sensor.
The optical code reader can be of the type comprising one or more LEDs as the light source and an optical illumination system for illuminating the optical code, and the optical sensor can be of the charge coupling device (CCD) type or of the complementary metal-oxide semiconductor (C-MOS) type for receiving the light signal coming from the code and transforming it into an electrical signal. Both types of sensor, moreover, can be of the linear or two-dimensional type. Alternatively, the reader can be of the type comprising a laser diode as the light source, an optical illumination system and scanning means for generating a scan and, therefore, illuminating the optical code, and the image sensor can comprise one or more photodiodes for receiving the light signal coming from the code and transforming it into an electrical signal. For both types of reader, the electrical signal representing the content of the code can be processed and decoded by a suitable processing system contained in the reader itself or separate from the reader, but connected to it through an electrical or radio connection.
U.S. Pat. No. 6,117,471 (King) describes a machine for preparing drinks using disposable cartridges. The cartridges are made from filtrating material and can be contained in a corresponding impermeable bag, which can be opened by the user or automatically. The machine comprises automatic positioning means of the cartridge in a brewing chamber, starting from a loading position, through a corresponding guide. The cartridge can be provided with an optical code that is read by a suitable reader when it is moved along the guide, before its insertion inside the brewing chamber. The optical code contains information that the reader sends to a controller of the machine: this information can, for example, communicate to the controller whether the cartridge can be accepted by the machine, whether the ingredients contained in the cartridge are fresh, or other information linked to the cartridge and to the material contained in it.
WO 01/58786 (Kraft) describes a cartridge structure containing ingredients for drinks (to be made through brewing), made from material impermeable to air and water, comprising a liquid entry point and a drink exit point. The cartridge comprises a shaped tank made from plastic hermetically sealed in the open part by a laminate sheet. The cartridge is provided with recognition means that allow the machine to set the correct preparation cycle of the drink. The recognition means can be an optical code printed on the lower side of the cartridge made from laminate sheet.
EP 334,573 (General Foods) describes a machine for making drinks using disposable cartridges. This document is cited in document WO 01/58786 in which it is stated that the machine of EP 334,573 can be modified, associating it with an optical reader used to read codes printed on the cartridges. This patent describes a piece of equipment with extremely complicated kinematisms, which receives a cartridge in a brewing chamber, “gripping it” between two substantially parallel plates. When the cartridge is positioned between the two plates, the entry and exit points are perforated by corresponding means.
U.S. Pat. No. 4,858,523 (Helbling) describes a machine for preparing drinks. The machine is loaded with filtrating cartridges containing the ingredients for the drink, and comprises a microprocessor for controlling the preparation cycles of the drinks. Amongst the inputs that the microprocessor receives there is the one sent by an optical reader for barcodes printed on the casing of the cartridge, which communicates to the microprocessor the type of drink contained in the cartridge itself, determining its preparation cycle.
EP 1,163,869 (Fianara) illustrates a machine in which a (substantially frusto-conical) cartridge is inserted into a brewing chamber and held in its seat by corresponding locking means. The cartridge is perforated by suitable elements allowing the entry of the liquid and the exit of the drink.
EP 272,922 (General Foods) describes variously shaped cartridges comprising a plastic body sealed by a laminate sheet.
The problem forming the basis of the present invention is that of making the reading of an optical code provided on the cartridge more certain, more reliable and more repeatable.